Navien NCB300-28K, Installation & Operation Manual

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Installing the System Piping 23
The installation must be made by sufficiently qualified
technicians, authorised to do so. For correct installation, the
water mains installation must comply with the Water Supply
(Water Fittings) Regulations and Scottish Water Byelaws,
together with all other national and/or local regulations
applicable at the time of installation. However, the following
recommendations must be complied with:
●
Before connecting the boiler hydraulically, the inside of the
pipes must be thoroughly cleaned, removing all sediment of
any type which could cause oxidation or damage to the heat
exchanger.
●
It is recommended to fit full bore shut-off valves to the
heating installation output and return pipes, to avoid having
to drain the installation when maintenance work is carried out
on the boiler.
●
Bleed the air from the boiler and heating installation. Ensure
there is no air in the heating circuit.
●
The NCB300 boiler is a condensing boiler, and it is therefore
essential for the condensate outlet to lead to a drain,
in compliance with all applicable national and/or local
regulations to this respect.
●
The boiler drain must not be located above a window, entry
door or other public point of access. Bear in mind that boiling
water or steam could come out when draining.
●
Draining must be done in a downward direction and towards
the walls.
●
When connecting or using an underfloor heating system,
designed with plastic pipes, or plastic pipes are used
elsewhere in the installation, one should ensure that the
plastic pipes used comply with the DIN 4726/4729 standard. It
is set out in this standard that the pipes may not have oxygen
permeability higher than 0.1 g/m³.d at 40°C. If the system
does not comply with this DIN standard, the underfloor
heating component will have to be separated from the central
heating appliance by means of a plate exchanger.
WARNING
●
Tighten the boiler water connections, taking care not
to damage them. Do not force the tube connections
excessively, as this could damage the connections and
cause leaks.
●
Any dirt in the tubes could reduce boiler efficiency and
cause it to malfunction.
●
Any pipes exposed to the elements or which could freeze
in winter must be insulated with suitable insulating
material.
CAUTION
Failure to follow the instructions provided in this section will
void the warranty and may result in property damage, fire
or serious injury.
4. Installing the System Piping
4.1 Installing a Central Heating System
The primary and secondary heat exchangers of the Navien
NCB300 boiler are designed to attain the highest level of
heat transfer in a compact design. To accomplish this, the
heating water flows through a series of tubes (secondary
heat exchanger) and finned tubes (primary heat exchanger),
designed to maximise the heat transfer area. To maintain the
efficient and reliable operation of the heat exchangers, and to
avoid heat exchanger failure, it is critical to ensure the rules and
guidelines in this section are followed.
CAUTION
●
The installation must be made by sufficiently qualified
technicians, authorised to do so.
●
For correct installation, connect the central heating
system according to the current regulations together
with all other national and/or local regulations applicable
at the time of installation.
Refer to the following illustration for a typical DHW piping
example for the boiler.
Union
CH Flow
CH
Return
Bottom View
Floor Heating Circuit or
Heating Circuit (Radiator)
Heating Supply
Adapter
Heating Return
Adapter
When connecting the central heating system, follow these
guidelines:
●
Tighten the connection valves with care to avoid damage.
●
Test the boiler for proper central heating flow and inspect for
leaks.